Running Store guy with 13 years in the industry chiming in...
Brooks is killing it because the Ghost, Glycerin and Adrenaline have been consistently good year after year for so many people and when they update those three models they make the smallest changes possible so as not to ruin the shoe for their loyal customer base.
Hoka is killing it because people are wearing running shoes as general lifestyle shoes as well and you can feel the cushion and support of their shoes but they somehow aren't heavy clunkers like you would imagine them to be when looking at them on the wall. For better or worse, they've engineered themselves into a corner (IMO) with the Clifton, Bondi, Arahi and Gaviota so when new models come out it's really just a matter of making sure the fit is still comfortable in your tried and true model or if you need to adjust the size or simply switch to a different model. Grassroots advice from family/friends/colleagues has been driving interest for the last 7-8 years and when you get used to having that much stuff under your foot it just doesn't feel the same. Hoka has also done a smashing job of their courting the younger generation of shoppers and convincing them that all white Cliftons are the IT shoe to have...case in point, go to any college/university. This crowd doesn't want their parents' shoes.
On hit the scene with something that was strikingly different and catered directly to lifestyle wear. Their newer models - Go, Monster, updated Surfer and Flow, in particular - do a great job of giving legit runner options that are also comfy and stylish lifestyle.
All the other brands you mentioned have focused almost exclusively on catering to the runner crowd, but it's the lifestyle/comfort and medical referral crowds that is truly driving the Run Specialty industry.